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On a Dell SAS 5/ir RAID controller, I have a RAID 1 array which is Degraded.

One drive has failed.

Upon replacing this drive the controller doesn't automatically resync the array.

There's an option to manually add the new drive to the array, but when I try this, the controller bios shows:

Screenshots: http://imagebin.ca/view/QdCuJI5.html

WARNING! Data on physical disks that are part of the virtual disk will be LOST! Are you sure you want to commit RAID Configuration changes?

Now - it is obvious that the drive I put in to replace the failed one will have data loss, as it should get data from the working drive synced onto it.

However, the Controller's message doesn't state what drive there'll be data loss. It could be that making this change will create a fresh RAID LUN with no data. I don't know, and the controller doesn't make it clear.

Can anyone say for definite that this will not affect the data on the original drive?

It just worries me that the message states "physical disks" - plural, and not "Data on the secondary physical disk that you just added will be LOST!"

No doubt this is what the message means, but I don't like guessing with critical data!

Many thanks!

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poking around with the megacli tool may help: tools.rapidsoft.de/perc –  cagenut Jun 22 '10 at 15:53

3 Answers 3

up vote 3 down vote accepted

Having come across the same issue on an identical platform again, with no valuable data, I decided to see what would happen and just pressed "Commit Changes" after being given that warning.

It turned out that this does did not lose the array, and added the new disk to the existing raid 1 array, as expected.

As I suspected, the error message was just too vague: it should have stated that "You will lose data on the new member disk that you are about to add to the existing array, the existing drive will not be touched'.

Potentially they made the error message intentionally vague so they could re-use it.

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It states that the data on the physical disk will be lost, not the data on the virtual disk. Now, I'd be nervous if I where in your situation as well so I'd give dell a call. be sure you get someone who actually understands what you're doing and what hardware you're running, though.

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I've called dell several times now, and their Pro Support can't seem to give me a definite answer. –  Kenny Jun 22 '10 at 9:30
1  
Anyway....backup all data before do anything! –  lg. Jun 22 '10 at 15:05
    
@Kenny That's weird. Some of their tech are definitely not competent but that seems to be pushing it. Call them again and ask to talk to a manager. Anotehr way is to call your account manager and explain the issue: he'll me able to escalate it and get you in touch with someone who knows the difference between a PERC 6/i and a StarTech SATA "RAID" –  Stephane Jun 23 '10 at 8:59

Two things in that message tell me that you'll lose your data:

Data on physical disks that are part of the virtual disk will be LOST!

This would seem to indicate that all phyisical disks that are members of this particular virtual disk will be wiped out.

Are you sure you want to commit RAID Configuration changes?

Replacing a failed RAID member disk should not result in a RAID configuration change.

My suggestion would be to call Dell tech support again, explain to them everything you've done, and find out how to replace the failed member disk without losing the array.

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Thanks. I phoned Dell ProSupport many times, and they were all vague and didn't know the answer. –  Kenny Nov 23 '10 at 10:36

protected by Community Jul 1 '11 at 3:01

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